On my 2010 4x4 TRD Off Road, I intermittently feel what seems like a slight "bump" in the driveline as I come to a stop. When I release the brakes to start off, and again intermittently, I feel another "bump" that is something like a transmission downshift taking up slack. I say "bump" because on the start up it often feels like the truck just received a light tap from the rear. What's significant is that it doesn't happen all the time and I haven't figured out how to make it happen when I want it to.

I had the TSB for the downshift on turns problem done back in January, but this phenomenon didn't come up until well after that work was done. In fact, if there is any pattern to what is happening it's that it increases in frequency and severity as ambient temperature rises above 95 degrees.

I don't think this is normal, but before I take the truck to the dealer I wonder if anybody has any ideas as to what is going on.

Sounds like axle wrap to me; but then again, when I read "thump", "clunk", or "bump" I immediately think as much. Your truck sounds too new to be experiencing axle wrap...but who knows. Try a search on here for "axle wrap" or "axel wrap". Good luck.